Answer:
√10 / 10
Step-by-step explanation:
tan θ > 0 and sin θ < 0, so θ is in quadrant III. That means cos θ < 0.
cos(θ + π/4)
Use angle sum formula.
cos θ cos(π/4) − sin θ sin(π/4)
½√2 cos θ − ½√2 sin θ
Factor.
½√2 cos θ (1 − tan θ)
½√2 cos θ (1 − 2)
-½√2 cos θ
Write in terms of secant.
-½√2 / sec θ
Use Pythagorean identity (remember that cos θ < 0).
-½√2 / -√(1 + tan²θ)
-½√2 / -√(1 + 2²)
½√2 / √5
√10 / 10
Answer:
The bottom of a river makes a V-shape that can be modeled with the absolute value function, d(h) = 1/5|h - 240| - 48, where d is the depth of the river bottom (in feet) and h is the horizontal distance to the left-hand shore (in feet).
Step-by-step explanation:
The point-slope form:

We have the points (5, -3) and (-2, 9). Substitute:

The first expression is equivalent to B
The second expression is equivalent to A
The third expression is equivalent to C
You are basically adding like terms. For example for the first expression, it is 7x^2 + 2x^2, which equals 9x^2. Remember since you're adding, do not add the exponents.